Young children are taught simple gestures for words and phrases to communicate their everyday needs, such as “milk”, “more”, “all gone”, “food” and “tired”.

It is claimed that the technique brings numerous benefits, including improving the bond between mother and child, aiding language development, reducing crying and even increasing a child’s intelligence.

But research from Hertfordshire University has found “no evidence that using baby signing… helps to accelerate their language development”.

In the first randomised control trial of the system, 40 mothers – most educated to degree level – were recruited with their eight-month-old babies.

Half of the sample was taught a list of gestures and half were assigned to a group where no signing was taught.

Each baby’s development was tracked over a 12-month period.

The findings – published in the journal Child Development – appeared to contradict some claims made by companies promoting baby signing.

Dr Liz Kirk, from Hertfordshire’s department of psychology, who wrote the report, said: “Although babies learnt the gestures and used them long before they started talking, they did not learn the associated words any quicker than the non-gesturing babies, nor did they show enhanced language development.”

The new research did reveal that introducing baby signing could encourage parents to “think of their baby as an individual with a mind” and respond to their non-verbal clues.

The academic added: “Baby signing has become big business and mothers, particularly first time mums or less confident parents, feel the pressure to do it.

“Some even think 'if I don’t do it and everyone else is, I must be a bad mother’.

“But the claims of language acquisition in previous, less rigorous studies, must be treated with caution. You really cannot improve on stimulating homes where attentive parents talk to their children.”

But baby signing experts contradicted the findings.

Wendy Moat, 45, a qualified nursery teacher from Lincoln, who has been running baby signing classes for three years, said that the sessions encouraged speech development, enhanced early vocabulary and may help develop a higher IQ.

She said: “So many mums attribute the fact that their toddlers talk so well to doing baby signing when they were babies.

“I saw a little girl of 19 months recently who had come to my classes and her vocabulary is incredible. She can talk in sentences and go through an entire book with her mum picking everything out.